There are many other theories of consciousness
besides those described on the 'people' pages, some of them serious
contenders, others less likely. Are traditional ideas about souls
and spirits right after all? Could consciousness have arisen through
the breakdown of the bicameral mind in historical times? Is it all
down to memes, or just a matter of
different levels of explanation? Perhaps consciousness is simply a
higher-order mental process - thoughts about thoughts? Here are a few
of the most interesting and appealing
theories.

Reality
is not simple. In biology, for example, even the most thorough-going
materialist would accept that there are interesting things to be said
about cells, organisms, and species which cannot be boiled down to a
bald account of atoms and forces - though at the same time we
never doubt for a moment that in some
sense mere physics provides all the ingredients biology requires. It
is just a fact about the world that it operates on these
different levels - a fact nicely captured in Mary Midgeley's slogan 'one
world, but a big one'. This multiplicity of levels does not normally bother
us or cause us to start fretting about the
reality of cells or organisms, so why can't we just see
conscious thoughts and motives as another level of explanation and leave it
at that?

For one thing, we don't know yet exactly how
consciousness relates to the atoms-and-forces version. In the case of
cells and organisms we understand pretty well how the parts fit together
and how the properties of the cell, say, arise from the nature of the
atoms making it up and the relationships between them. In the
case of consciousness, we just haven't got that far yet. Even when we do,
I think more will still be required by way of explanation than just
saying that consciousness is a matter of different levels of
interpretation. We need to know how it works.
What makes matters worse is the especially large
and vigorous group of false theories
and ideas about consciousness that have to be denounced and
eliminated. We can afford to be a bit more laid back about the
materialist account ofcells and
organisms because it isn't seriously challenged by
anyone.

Anyway, this general view of reality as having
a number of different levels also provides the basis for two much-quoted
ideas: reduction and emergence. A reduction of a phenomenon, or a
reductive explanation, accounts for higher-level properties so
thoroughly in terms of lower-level entities that it is no longer strictly
necessary to consider the higher level - in fact the reality of the higher
level entities may be challenged. The classic example, perhaps, is
temperature and mobility of molecules. Once it was understood that the two
were the same, it became clear that there really wasn't anything to
temperature except the motion of molecules. Another example might be the
periodic table, which allowed the whole of chemistry to be reduced to
physics, and indeed, some new chemistry to be discovered by extrapolation.
Sometimes theories of consciousness are criticised for being too reductive
- attempting to abolish consciousness as something real in its own right.
On the other hand, appropriately reductive explanations are among the best
you could have.

Emergence is sort of the opposite. An
emergent phenomenon is a higher-level one which could not have been
foreseen from the lower-level account, or at least, one which amounts to
more than the simple conjunction of lower-level entities. It's often
suggested that consciousness is an emergent phenomenon, though without a
theory of how it emerges, that doesn't tell us much.

First order thoughts are
straightforward thoughts - 'There's a chair.'. Second order thoughts are
thoughts about thoughts - 'I knew that was a chair ...'. Quite
high-order thoughts are actually relatively common: 'I can't imagine
why you thought I even cared whether he shared my taste in
chairs?' - fifth order?

Anyway, an idea which recurs in several different
contexts is that consciousness has something to do with higher order
stuff: either our awareness of ourselves or thoughts about
thoughts. Self-awareness is often considered a special, or even the only
true, form of consciousness. Great significance has been attached to
experiments which seem to show that while most animals treat their
reflection in a mirror as another animal, some of the great apes
realise that it is themselves they see (they betray this awareness by
reaching up to touch a spot on their faces which they
were unaware of until they looked in the mirror). Perhaps the
influence of Descartes ('I think, therefore I am' has something to do
with the special place which thoughts about ourselves have been
given. For sceptics it is also appealing to think that the impression
of self-hood might come from turning on ourselves
a faculty which developed
to help us respond appropriately to other organisms. The idea that containing a
representation of oneself is sufficient for consciousness has been very
effectively ridiculed by Roger
Penrose , however, who asks scathingly
whether a video camera pointing at a mirror is to be regarded as
conscious.

The idea that higher order
thoughts are special - that conscious thoughts are those we are aware
of thinking - remains very appealing. Higher order processes certainly
crop up incidentally in many theories about the mind (Searle'

s idea that
intentionality is characterised by the imposition of
conditions of fit on conditions of fit, for example) and few
would deny that they are at least a
feature of consciousness. The view that they are essential to it can
be traced back as far as Locke, and comes in many different forms.
One school of thought here is that conscious thoughts are somehow
inherently about themselves as well as about their other targets; another
version, expounded by David Rosenthal, maintains that thoughts are only conscious
when there is a separate higher-order thought (HOT) about them. Neither view sits completely happily
with the normal perception that most of our conscious thoughts are just
not that complex. Many other issues also remain open - do we need thoughts
about thoughts to be conscious, or will perceptions of our thoughts
do? Higher-order theories are generally compatible with other
theories about the nature of consciousness, and perhaps this is in the end
why they haven't made more impact - no-one has succeeded in
formulating them in a way which makes them controversial enough to be
really interesting.

If you ask me, these ideas are in any case inherently less interesting than they seem. The
point is, second order thoughts or processes are about
thoughts or processes. So to have them, you have to have aboutness -
intentionality. But intentionality is one
of the two big issues about consciousness, and this blather about
second-orders takes it for granted rather than helping to solve it.
If you like, higher-order theories are pursuing the flea on the back of
the bear of intentionality. If we ever catch the bear, the fleas will come
along with it, but catching the fleas wouldn't mean we'd caught the bear,
though while the bear's still at large, it's just as difficult.

But
you can have higher-order theories which don't presuppose intentionality.
Take Edelman. According to him the
process starts with the recategorisation of sensory inputs: then the
categories themselves are recategorised to form concepts. Concepts of
concepts take us up to second-order consciousness and self-consciousness,
and concepts form the basis for language.

OK, but Edelman has the opposite
problem - not actually explaining intentionality. Why are higher-order
categories any more meaningful than lower-order ones? Why would a group of
neurons which responds to a group of sheep be more conceptual than a group
of neurons which responds to one? I don't see it.

It is remarkable how poor a showing the whole idea of
immaterial spirits now gets in both science and philosophy: after all, for
many centuries most Europeans, including the brightest and most
sophisticated thinkers, took it for granted that the explanation of
consciousness lay in a spiritual realm, whereas now, as Searle has said
about the existence of God, it isn't so much that everyone is a sceptic as
that the question never even arises. Given that ideas from
the Christian tradition are rather poorly served, it can hardly be
surprising that other religious views are scarcely reflected at all
in contemporary Western discussions of consciousness, in spite of
the undeniable interest of many of them. In these pages we are
currently no better than anyone else in this respect (but at least we
are ashamed of ourselves).

However, the spiritual
view does have one able and well-qualified scientific champion in the
shape of Sir John Eccles. His credentials, and in other respects, his
scientific orthodoxy, are unchallengeable, but he holds that the
materialist account of the brain falls short of a full explanation
and proposes a neurologically sophisticated alternative
account.

Eccles' partner in
developing and promulgating his theory was Sir Karl Popper, the eminent
philosopher of science, and his account has a philosophical and an
empirical scientific side which require separate consideration. In this
respect it resembles the views of Roger Penrose, and the
two theories also have in common an appeal to quantum physics and an
advocacy, not just of dualism, but of a three-world system. There the
resemblance ends, however.

Scientifically, Eccles
and Popper argued that there is empirical evidence for a distinction
between brain and mind. When the brain is stimulated with electrodes,
images and memories can be evoked in the mind without shutting
off the normal mental processes of perception and recollection.
Surely this represents, on the one hand, images streaming up from the
purely physical brain, and on the other, perceptions streaming down from a
mind which can only be immaterial? Or take the example
of ambiguous drawings with more than one interpretation: the
brain, by itself, chooses one or other interpretation and presents
the image to the mind in that light: but we can often choose to see
the ambiguous image the other way, which surely represents the
intervention of something else in the purely physical processing
carried out by the brain. According to Eccles, the mind has access
to a range of different brain processes, and by directing
attention between them (like a searchlight) brings about the unity of
consciousness which would otherwise be inexplicable given the diverse and
complex nature of neural processes.

Specifically, Eccles suggests that spiritual
psychons interact with presynaptic vesicular grids by a process
analogous to the
probability fields of quantum physics. A kind of spiritual cerebral cortex
interacts with the physical one undetectably but effectively at thousands
of tiny sites. This allows interaction between mind and brain
without violating the conservation laws of the physical world, while
preserving the autonomy of the spiritual world, or 'World
2'.

World 2 is one of three
worlds proposed by Eccles and Popper: World 1 is the world of physical
objects; World 2 is that of states of consciousness and subjectivity (the
world of qualia, presumably); World 3 is a Platonic one of objective
knowledge and culture. However, the third world does not play an essential
role in the theory, with the key interest being the interaction between
worlds 1 and 2.

The theory remains
vulnerable to the usual avenues of attack on dualism. By confining the crucial
interactions to micro-sites where the minute interventions are effectively
undetectable, Eccles guarantees that there can be no clear and direct
physical evidence of the interventions (one might suspect that the theory
is designed this way exactly to accomodate the absence of such evidence).
The actual mechanism remains rather obscure - we are offered only the
analogy of probability
fields. But probability fields don't cause physical events; they just
describe them. If the theory is a matter of probability fields, or
something like them, it's surely more a matter of another level of
explanation rather than another world.

We are offered little about how World 2 might work,
but the psychons seem to be very similar to the neurons with which they
interact. They seem to have definite physical locations, or at least something
that allows them to associate separately and individually with
particular physical sites. They must also have something
like standard causal interactions between themselves in order to
co-ordinate their handling of thousands of different micro-sites at a
time. But the contents of World 2 are not meant to be another set of
objects like the objects in World 1 - they are meant to be subjective
states of consciousness. Are psychons states of consciousness? Either the
theory is metaphysically stranger than it seems, or something is wrong
here.

Ultimately, it seems that the convictions of Eccles and Popper rest
on a kind of Brentano-style incredulity - it just seems obvious to them
that nothing physical can possibly account for the mental. The arguments put
forward about illusions and direct stimulation of the brain merely
establish that consciousness can have two levels or two sets of contents,
not at all that either must be non-physical: but the weakness of the argument
is hidden from its proponents by their intuitive certainty that subjective
consciousness is not physical.

The theory must remain unconvincing to those
who don't share this intuitive certainty: but at least it does serve to
show that dualist or spiritual theories need not be a matter of ignorant
superstition about 'spooks'.

In his
celebrated book 'The Selfish Gene' Richard Dawkins digressed to suggest that evolution might have
another string to its bow besides genetics. Perhaps there was also
cultural evolution. He proposed that in culture the analogue of the gene
should be a 'mimeme', a unit of imitation - though Susan Blackmore
says the kind of imitation involved is not in fact mimesis. In any case,
Dawkins settled on the shortened form 'meme'.

Dawkins' original presentation of the idea had a relatively casual
tone, and he acknowledges that the analogy with normal biological
evolution is not perfect. His main concern seemed to be with those cases
where some error or unwanted thought succeeds in perpetuating itself in
spite of being wrong or unwelcome - tunes which stick in your mind even
though you don't actually like them, for example. These are clearly the
interesting cases, anyway - we don't need a special explanation for
the persistence of good or attractive ideas, and couldn't prove in
such cases that distinctively memetic processes were at
work.

Memes have been taken very seriously by other
authors, however, and given a much wider application. In particular, Susan
Blackmore in 'The Meme Machine' has tried to straighten out some of the issues and use the
basic idea to explain a wide range of mental phenomena in
memetic terms. She proposes that the self is an illusion
(does this make her a ghost-writer?) generated by a self-protecting
complex of memes. She believes that consciousness is an illusion too, not
in the sense that it doesn't exist at all, but in the sense that we
falsely attribute it to a more or less homuncular central
observer(though surely belief in the self
does not automatically imply belief in an homunculus or Dennettian
Cartesian Theatre ). She believes that there is a
non-memetic bedrock of consciousness in pure phenomenal
experience. This leaves her with the epiphenomenalist view that our ideas don't originate from our own real
consciousness, however.

On the face of it, Dennett is bolder, asserting
that our consciousness is made up of memes, or more exactly, meme effects
in brains. It's a bit strange that Dennett, who already has one theory on
the go, should embrace memes quite so enthusiastically. One would expect
him to hold that memes are just things we attribute to each other in the
course of trying to predict behaviour: that consciousness allows 'our
hypotheses to die in our stead', rather then our hypotheses running
us for their own benefit. The theory of the intentional stance does
not seem to be dependent on memes, anyway, so perhaps it's best to
assume that for Dennett memes are really just a lively
metaphor...

For Dennett,
people are just lively
metaphors...

... an illuminating way of describing processes
which could,
however, be fully described in
other terms if necessary.

There
are other objections to the whole idea of memes, but a full discussion
goes beyond the scope of these pages. From our point of view the main
problem is with memes as
a
general theory of psychology: it's too obvious that our minds don't normally work like that. There
might be something interesting to be said about the evolution of urban myths, jokes, or
superstitions through accumulated variations (perhaps we could tell the age of
a story from the number of variations
current, rather in the way biologists age hedgerows by counting the number
of plan species), but it's not at all plausible to think that
we conduct conversations, write novels and philosophical papers, or
conduct scientific research, by copying past material over and over again
until the errors accumulate into a new and better version. We do these
things, not through a series of accidents, but deliberately - consciously,
in fact. If memes explain anything, it must surely be unconscious
processes.

One of the most
original theories of consciousness is the one put forward by Julian Jaynes
in "The Origin of Consciousness in the Breakdown of the Bicameral
Mind". It's also, at first sight, one of the least plausible: Jaynes
maintains that consciousness did not arrive until some time after the
writing of the Iliad. Up to
that point everything done by human beings was, strictly speaking, done
unconsciously.

How on earth could that be so?
According to Jaynes, the minds of our ancestors were split into two
distinct chambers (a bicameral structure) with one chamber in regular
control and the other making occasional, authoritative interventions. What
we now perceive as our own integrated conscious thoughts seemed to our
more distant ancestors like voices in the head, actually from the second
chamber, but attributed to spirits in the world around them; voices
which they had little or no power to disobey. In later periods, the voices
came to be identified as belonging to a dead king; first a recently-dead
corpse propped up on a couch of stones, then an increasingly permanent
god-figure in a tomb which gradually became a temple. This development
co-incided with, and made possible, the development of larger and more
complex communities than had previously existed. Only later did people
gradually come to realise that these internal voices actually belonged to
them as much as their normal external speech.

This business of having voices
in the head clearly resembles some contemporary forms of mental illness.
Jaynes certainly thinks the process was subject to occasional reversion,
with Joan of Arc, for example, hearing divine voices in pretty much the
way her remote ancestors had done. He discusses schizophrenia and
hypnosis, both possible relics of the bicameral mind in his view. He also
suggests that this kind of internal conversation represents one hemisphere
of the brain talking to the other.

Jaynes is a persuasive
writer, with an impressive breadth of reference and a clear, rational
style. It is impossible, I think, to read his book without feeling that he
does have a valid point to make about ancient ways of thinking. It is a
testament to his plausibility that there is a society dedicated to his
views.

Nevertheless, after
the immediate spell has worn off, I think his views about consciousness
end up seeming almost as implausible as they did to begin with. Probably
it is true that many ancient societies tended to see human behaviour as
god-driven in a way which made the constant divine intervention of the
Iliad a natural part of a story. By the time Virgil was writing in a
similar vein, it had come to be a rather artificial literary convention:
and by Swift's day it could only really be used for comic or satirical
effect. But does that imply a fundamental reorganisation of the mind or
just the gradual obsolescence of a literary convention? Our minds and
literature are not filled with gods, but with brand names, advertising
slogans, and the clichés of Hollywood and television - but would that
justify a future researcher in concluding that we were unconscious robots,
obeying the 'voices' of large commercial corporations? Hmm... Jaynes
maintains, probably with some justice, that many ancient texts seem to
display a modern cast of mind only because the translator
has reinterpreted them; but surely this reinterpretation could not go
so far as to make the unconscious seem conscious?

Perhaps the real sticking
point is Jaynes' view that language and literature preceded consciousness.
There are many tasks we can and do carry out without paying much
deliberate attention, but surely speech and above all, literary
composition, don't fall into that category? Far from explaining
consciousness, Jaynes' view seems to require that there were two spheres of consciousness in
the ancient mind. Since the god-like chamber 'spoke' to the everyday one,
and the everyday one was apparently capable of writing the Iliad (and
large parts of the Bible), it seems that both would
have been able to pass the Turing test, anyway. When I seek an
explanation for consciousness, it is, among other things, the
processes of imagination and composition which go into the creation of a
text which I want to have explained. Even if I agreed to stop calling
these processes conscious, the essential mystery would remain
untouched.